US9501728B1

Movatterモバイル変換

Info

Publication number: US9501728B1
Application number: US15/177,356
Authority: US
Inventors: Takuya Ishikawa
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 2015-12-04
Filing date: 2016-06-09
Publication date: 2016-11-22
Anticipated expiration: 2035-12-04
Also published as: US9389813B1; US9633289B1; US20170161597A1; US9665318B1

Abstract

A method for minimizing power consumption of a laser printer includes receiving page description language (PDL) data corresponding to a printing task, identifying commands corresponding to the received PDL data, computing a total predicted rendering time corresponding to the identified commands, computing a print deferral time according to the total predicted rendering time wherein the print deferral time corresponds to an amount of time by which printing drum initialization can be deferred without delaying completion of the printing task, and configuring a printing drum to begin operation according to the print deferral time. A computer program product and computer system corresponding to the method are also disclosed.

Description

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of laser printing, and more specifically to increasing efficiency in laser printing tasks.

Laser printing is an electrostatic digital printing process which produces texts and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylindrical drum to define a differentially-charged image. The drum then selectively collects electrically charged powdered ink, or toner, and transfers the image to paper, which is then heated in order to permanently fuse the text and/or imagery. Laser printers receive data from a computer, and perform rendering and drum printing on the received data.

SUMMARY

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram depicting one embodiment of a laser printing system in accordance with some embodiments of the present invention;

FIG. 2 is a flowchart depicting one embodiment of a drum initialization delay method in accordance with some embodiments of the present invention;

FIG. 3A depicts a laser printing timeline before drum initialization is deferred in accordance with one embodiment of the present invention;

FIG. 3B depicts a laser printing timeline after drum initialization is deferred in accordance with one embodiment of the present invention; and

FIG. 4 depicts a block diagram of components of a computer, in accordance with some embodiments of the present invention.

DETAILED DESCRIPTION

A printing drum and associated drum heater are energized only during times of active printing (while paper is moving) and for a few seconds for preheating. The power consumption of the drum and the heater are very large, making it beneficial to minimize the amount of time for which the drum and the heater must be energized. Current laser printing methods require the drum and heater to be operating during some periods when pages are not ready to be printed, which leads to unnecessarily long operation times. The embodiments disclosed herein may enable minimization of a printing drum operation time.

FIG. 1 is a block diagram depicting one embodiment of alaser printing system100 in accordance with some embodiments of the present invention. As depicted,laser printing system100 includes acomputer system110, adata source120, and anetwork130.Laser printing system100 may correspond to a system that can be made more efficient by a drum initialization delay method.

Computer system

110 can be a desktop computer, laptop computer, specialized computer server, or any other computer system known in the art. In some embodiments,computer system110 represents a computer system utilizing clustered computers and components to act as a single pool of seamless resources when accessed throughnetwork130. In general,computer system110 is representative of any electronic devices, or combination of electronic devices, capable of executing machine-readable program instructions, as described in greater detail with respect toFIG. 4.

As depicted,computer system110 may include aprinter driver112.Printer driver112 may be a piece of software that converts data to be printed to a form specific toprinter120.Printer driver112 enables other applications oncomputing system110 to carry out printing tasks without being aware of the technical details ofprinter120. In one embodiment,printer driver112 is configured to provide page description language data corresponding to a printing task toprinter120.

Printer

120 may be any peripheral which makes a persistent human readable representation of graphics or text on paper or similar physical media. In some embodiments,printer120 is a laser printer.Printer120 may be configured to receive a printing task fromcomputer system110 vianetwork130. As depicted,printer120 may includeapplication124.Application124 may be configured to execute a drum initialization delay method to limit the power consumption corresponding toprinter120. The details of the drum initialization delay method executed byapplication124 are described in greater detail with respect toFIG. 2. It should be appreciated that whileFIG. 1 depictsapplication124 as existing inprinter120, in other embodiments of thepresent invention application124 could be hosted on a computer system instead.

Network

130 can be, for example, a local area network (LAN), a wide area network (WAN) such as the Internet, or a combination of the two, and include wired, wireless, or fiber optic connections. In general,network130 can be any combination of connections and protocols that will support communications betweencomputer system110 andprinter120 in accordance with an embodiment of the present invention.

FIG. 2 is a flowchart depicting one embodiment of a druminitialization delay method200 in accordance with some embodiments of the present invention. As depicted, druminitialization delay method200 includes receiving (210) page description language data corresponding to a printing task, identifying (220) commands corresponding to the PDL data, computing (230) a total predicted rendering time of the commands, computing (240) a print deferral time, and configuring (250) a printing drum to begin operation at the print deferral time. Druminitialization delay method200 may enable increased efficiency in laser printing tasks.

Receiving (210) page description language (PDL) data corresponding to a printing task may include receiving PDL data from a printer driver. PDL data is data that describes the appearance of a printed page on a higher level than an actual output bitmap. PDL data may be textual or binary data streams. The received PDL data may include a plurality of fields, including a page number, color information, vector data, and image data corresponding to the printing task. Receiving (210) PDL data may further include dividing the received PDL data based on which page it corresponds to.

Identifying (220) commands corresponding to the PDL data may include analyzing the received PDL data to identify commands indicated by the PDL data. In one embodiment, identifying (220) commands comprises creating a list of all commands indicated by the PDL data and the number of occurrences of each command. The identified commands may be sorted according to the page to which they correspond.

Computing (230) a total predicted rendering time of the commands may include comparing the list of commands to a correspondence table of PDL commands and rendering times. The correspondence table may be a table that has been created in advance by applying PDL commands on a sample data set with respect to the relevant printer and measuring the rendering time associated with each command. For each identified command, a corresponding rendering time is identified within the correspondence table. The sum of the rendering times associated with commands on a page of the printing task may be calculated to provide an estimated rendering time for each page.

Computing (240) a print deferral time may include calculating a time at which a printing drum should begin printing pages corresponding to the printing task. The print deferral time may correspond to an amount of time by which printing drum initialization could be delayed to minimize the power consumption associated with the printing drum without delaying the completion of the printing task. In one embodiment, the print deferral time is applied with respect to an existing printing drum initialization time, which may correspond to the point at which the first page of the printing task has been rendered completely. The print deferral time T may be calculated according to the equation:
T=R₂+R₃+ . . . +R_N−(D₁+D₂+ . . . +D_N-1) (1)
With respect to equation 1, R_Ncorresponds to a rendering time associated with an nth page of the printing task, D_Ncorresponds to a drum printing time associated with an nth page of the printing task, and N corresponds to the total number of pages in the printing task. In some embodiments, the drum printing time is constant for all pages regardless of content, in which case the print deferral time T may be calculated according to the simplified equation:
T=R₂+R₃+ . . . +R_N−(N−1)*D (2)

Configuring (250) a printing drum to begin operation according the print deferral time may include sending a signal to the printer to begin operating at a point in time indicated by the print deferral time. In some embodiments, the print deferral time is calculated with respect to an existing drum initialization time corresponding to the first page of the printing task being completely rendered. In these embodiments, the printing drum initialization time to is calculated according to the equation:
t₀=R₁+T (3)

With respect to equation (3), R₁corresponds to the time taken to render the first page of the printing task, and T corresponds to the print deferral time as calculated according to equation (1) or equation (2).

FIG. 3A depicts alaser printing timeline300A before drum initialization is delayed in accordance with one embodiment of the present invention. As depicted,laser printing timeline300A includes a startingtime310, rendering times320, print times330, waiting times340,completion time350, and printingdrum engagement duration360.Laser printing timeline300A depicts the waiting times associated with initializing a printing drum as soon as a first page of a printing task has rendered.

Startingtime310 corresponds to a point at which a printer begins rendering a printing task. Atstarting point310, the printer begins rendering the first page, as indicated byrendering time320A.

Rendering times

320A,320B,320C, and320D correspond to times associated with rendering pages 1, 2, 3, and 4, respectively. Similarly,

print times

330A,330B,330C, and330D correspond to times associated with physically printing pages 1, 2, 3, and 4, respectively.

Waiting times340 correspond to periods of time during which the printing drum remains active but is unable to begin printing a next page. As depicted, the printing time330 associated with each page is significantly shorter than the associated rendering time320. For this reason, once a page is finished printing, the printing drum is forced to wait until a next page has finished rendering before it can begin printing a next page. The drum must be kept revolving and heated throughout the duration of the printing task, and therefore remains engaged during these wait times despite not being actively used.Completion time350 corresponds to a point at which the printer has finished printing all pages associated with the printing task, and the point at which the printing drum is disengaged. Printingdrum engagement duration360 corresponds to the period of time during which the printing drum is revolving and heated.

FIG. 4 depicts a block diagram of components ofcomputer400 in accordance with an illustrative embodiment of the present invention. It should be appreciated thatFIG. 4 provides only an illustration of one implementation and does not imply any limitations with regard to the environments in which different embodiments may be implemented. Many modifications to the depicted environment may be made.

As depicted, thecomputer400 includescommunications fabric402, which provides communications between computer processor(s)404,memory406,persistent storage408,communications unit412, and input/output (I/O) interface(s)414.Communications fabric402 can be implemented with any architecture designed for passing data and/or control information between processors (such as microprocessors, communications and network processors, etc.), system memory, peripheral devices, and any other hardware components within a system. For example,communications fabric402 can be implemented with one or more buses.

Memory

406 andpersistent storage408 are computer-readable storage media. In this embodiment,memory406 includes random access memory (RAM)416 andcache memory418. In general,memory406 can include any suitable volatile or non-volatile computer-readable storage media.

One or more programs may be stored inpersistent storage408 for access and/or execution by one or more of therespective computer processors404 via one or more memories ofmemory406. In this embodiment,persistent storage408 includes a magnetic hard disk drive. Alternatively, or in addition to a magnetic hard disk drive,persistent storage408 can include a solid state hard drive, a semiconductor storage device, read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, or any other computer-readable storage media that is capable of storing program instructions or digital information.

The media used bypersistent storage408 may also be removable. For example, a removable hard drive may be used forpersistent storage408. Other examples include optical and magnetic disks, thumb drives, and smart cards that are inserted into a drive for transfer onto another computer-readable storage medium that is also part ofpersistent storage408.

Communications unit

412, in these examples, provides for communications with other data processing systems or devices. In these examples,communications unit412 includes one or more network interface cards.Communications unit412 may provide communications through the use of either or both physical and wireless communications links.

I/O interface(s)414 allows for input and output of data with other devices that may be connected tocomputer400. For example, I/O interface414 may provide a connection toexternal devices420 such as a keyboard, keypad, a touch screen, and/or some other suitable input device.External devices420 can also include portable computer-readable storage media such as, for example, thumb drives, portable optical or magnetic disks, and memory cards. Software and data used to practice embodiments of the present invention can be stored on such portable computer-readable storage media and can be loaded ontopersistent storage408 via I/O interface(s)414. I/O interface(s)414 also connect to adisplay422.

Display

422 provides a mechanism to display data to a user and may be, for example, a computer monitor.

The programs described herein are identified based upon the application for which they are implemented in a specific embodiment of the invention. However, it should be appreciated that any particular program nomenclature herein is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature.

The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

The present invention may be a system, a method, and/or a computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.

Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.

These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.

The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The terminology used herein was chosen to best explain the principles of the embodiment, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

What is claimed is:

1. A computer program product comprising:

one or more non-transitory computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions comprising instructions to:

execute a set of possible commands in a printer rendering environment and calculating an average rendering time associated with each command of the set of possible commands to provide a rendering time table corresponding to the set of possible commands;

receive page description language (PDL) data corresponding to a printing task;

identify commands corresponding to the received PDL data;

compute a total predicted rendering time corresponding to the identified commands by extracting rendering times corresponding to the identified commands from a table indicating average rendering times associated with PDL commands;

compute a print deferral time according to the equation: T=R₂+R₃+ . . . +R_N−(D₁+D₂+ . . . +D_N-1), wherein T corresponds to an amount of time by which a printing drum initialization can be deferred without delaying completion of the printing task, R_ncorresponds to a rendering time associated with an nth page of the printing task, D_ncorresponds to a drum printing time associated with an nth page of the printing task, and N corresponds to the total number of pages in the printing task;

configure a printing drum to begin operation according to the print deferral time; and

execute the received printing task according to the print deferral time.